In recent years, attention has been increasingly paid to a display and a lighting device which use an OLED light-emitting element. Each of the OLED devices has a structure in which an organic light-emitting element is sandwiched by substrates on which a transparent conductive film such as an ITO film is formed. When an electric current flows through the organic light-emitting element in this structure, a hole and an electron in the organic light-emitting element are combined to emit light. The emitted light enters a substrate via the transparent conductive film such as an ITO film and is released out while repeating reflection in the substrate.